Hi nking,
Have you reset your EQ and Compressor settings? Having the volume up between three and five o’clock seems excessive. You may have a setting in the EQ that is incorrect for those speakers.
My volume usually stays around 9 o’clock with the Genos settings one of the members suggested to make the Tyros 5 have more punch like the Genos does. Before that I think I was usimg Gary’s EQ settings and my volume stayed at 12 o’clock. First try the factory setting in the EQ for those speakers and see if the distortion goes away. If it is still present, I would go back to where you bought them and get a new set under warranty.
Hope this helps,
Rick D.